Evaporation process is widely applied in the coating process for electronic devices. The principle of the evaporation process is to place a substrate for evaporation in a vacuum environment and deposit an evaporation material(s) on a surface of the substrate for evaporation for forming of film. Film formation areas of the substrate for evaporation are usually defined by mask strips.
In the evaporation process, if the edge of the substrate is scratched, the problems such as breakage of a peripheral circuit and package failure can be easily caused, so the yield and the service life of products can be disadvantageously affected. The scratching of the edge of the substrate is usually caused by the relative motion between the mask strips and the glass substrate during contact.
Currently, in order to solve the problem that the substrate can be easily scratched, on one hand, the sharpness and the roughness of edges of the mask strips are effectively controlled; and on the other hand, the relative motion between the mask strips and the glass substrate is slowed down, and the mutual acting force of the mask strips and the glass substrate is weakened. However, in order to ensure the flatness requirement in the contact of the mask strips and the glass substrate, the thickness of the mask strips is generally 100 μm or less, so the edges of the mask strips will be inevitably sharp. The mask strips are manufactured by an etching process, and it is greatly difficult to control the sharpness and the roughness of the edges of the mask strips by adjusting the parameters of the etching process.